diff --git a/Source/Android/jni/MainAndroid.cpp b/Source/Android/jni/MainAndroid.cpp
index 47a653d927..62d31580e7 100644
--- a/Source/Android/jni/MainAndroid.cpp
+++ b/Source/Android/jni/MainAndroid.cpp
@@ -87,13 +87,13 @@ void Host_RefreshDSPDebuggerWindow()
 {
 }
 
-void Host_Message(int Id)
+void Host_Message(HostMessageID id)
 {
-  if (Id == WM_USER_JOB_DISPATCH)
+  if (id == HostMessageID::WMUserJobDispatch)
   {
     s_update_main_frame_event.Set();
   }
-  else if (Id == WM_USER_STOP)
+  else if (id == HostMessageID::WMUserStop)
   {
     s_have_wm_user_stop = true;
     if (Core::IsRunning())
diff --git a/Source/Core/Common/Common.h b/Source/Core/Common/Common.h
index b1f7207734..d6a2210158 100644
--- a/Source/Core/Common/Common.h
+++ b/Source/Core/Common/Common.h
@@ -57,13 +57,3 @@ struct CrtDebugBreak
 // Dummy macro for marking translatable strings that can not be immediately translated.
 // wxWidgets does not have a true dummy macro for this.
 #define _trans(a) a
-
-// Host communication.
-enum HOST_COMM
-{
-  // Begin at 10 in case there is already messages with wParam = 0, 1, 2 and so on
-  WM_USER_STOP = 10,
-  WM_USER_CREATE,
-  WM_USER_SETCURSOR,
-  WM_USER_JOB_DISPATCH,
-};
diff --git a/Source/Core/Core/Core.cpp b/Source/Core/Core/Core.cpp
index b2af42fd3a..78a6e2f51a 100644
--- a/Source/Core/Core/Core.cpp
+++ b/Source/Core/Core/Core.cpp
@@ -291,7 +291,7 @@ static void CPUSetInitialExecutionState()
     SetState(SConfig::GetInstance().bBootToPause ? State::Paused : State::Running);
     Host_UpdateDisasmDialog();
     Host_UpdateMainFrame();
-    Host_Message(WM_USER_CREATE);
+    Host_Message(HostMessageID::WMUserCreate);
   });
 }
 
@@ -924,7 +924,7 @@ void QueueHostJob(std::function<void()> job, bool run_during_stop)
   }
   // If the the queue was empty then kick the Host to come and get this job.
   if (send_message)
-    Host_Message(WM_USER_JOB_DISPATCH);
+    Host_Message(HostMessageID::WMUserJobDispatch);
 }
 
 void HostDispatchJobs()
diff --git a/Source/Core/Core/Core.h b/Source/Core/Core/Core.h
index 51537f2ce9..4b53cb445b 100644
--- a/Source/Core/Core/Core.h
+++ b/Source/Core/Core/Core.h
@@ -100,7 +100,7 @@ void UpdateWantDeterminism(bool initial = false);
 void QueueHostJob(std::function<void()> job, bool run_during_stop = false);
 
 // Should be called periodically by the Host to run pending jobs.
-// WM_USER_JOB_DISPATCH will be sent when something is added to the queue.
+// WMUserJobDispatch will be sent when something is added to the queue.
 void HostDispatchJobs();
 
 void DoFrameStep();
diff --git a/Source/Core/Core/FifoPlayer/FifoPlayer.cpp b/Source/Core/Core/FifoPlayer/FifoPlayer.cpp
index fc2ce96808..d6c249293c 100644
--- a/Source/Core/Core/FifoPlayer/FifoPlayer.cpp
+++ b/Source/Core/Core/FifoPlayer/FifoPlayer.cpp
@@ -112,7 +112,7 @@ public:
       {
       case CPU::State::PowerDown:
         CPU::Break();
-        Host_Message(WM_USER_STOP);
+        Host_Message(HostMessageID::WMUserStop);
         break;
 
       case CPU::State::Stepping:
diff --git a/Source/Core/Core/HLE/HLE_Misc.cpp b/Source/Core/Core/HLE/HLE_Misc.cpp
index bcbf36afa8..bfba82ed24 100644
--- a/Source/Core/Core/HLE/HLE_Misc.cpp
+++ b/Source/Core/Core/HLE/HLE_Misc.cpp
@@ -25,7 +25,7 @@ void HBReload()
 {
   // There isn't much we can do. Just stop cleanly.
   CPU::Break();
-  Host_Message(WM_USER_STOP);
+  Host_Message(HostMessageID::WMUserStop);
 }
 
 void GeckoCodeHandlerICacheFlush()
diff --git a/Source/Core/Core/Host.h b/Source/Core/Core/Host.h
index acbea49ef7..ae14bb686f 100644
--- a/Source/Core/Core/Host.h
+++ b/Source/Core/Core/Host.h
@@ -8,25 +8,34 @@
 
 // Host - defines an interface for the emulator core to communicate back to the
 // OS-specific layer
-
+//
 // The emulator core is abstracted from the OS using 2 interfaces:
 // Common and Host.
-
+//
 // Common simply provides OS-neutral implementations of things like threads, mutexes,
 // INI file manipulation, memory mapping, etc.
-
+//
 // Host is an abstract interface for communicating things back to the host. The emulator
 // core is treated as a library, not as a main program, because it is far easier to
 // write GUI interfaces that control things than to squash GUI into some model that wasn't
 // designed for it.
-
+//
 // The host can be just a command line app that opens a window, or a full blown debugger
 // interface.
 
+enum class HostMessageID
+{
+  // Begin at 10 in case there is already messages with wParam = 0, 1, 2 and so on
+  WMUserStop = 10,
+  WMUserCreate,
+  WMUserSetCursor,
+  WMUserJobDispatch,
+};
+
 bool Host_UINeedsControllerState();
 bool Host_RendererHasFocus();
 bool Host_RendererIsFullscreen();
-void Host_Message(int Id);
+void Host_Message(HostMessageID id);
 void Host_NotifyMapLoaded();
 void Host_RefreshDSPDebuggerWindow();
 void Host_RequestRenderWindowSize(int width, int height);
diff --git a/Source/Core/DolphinNoGUI/MainNoGUI.cpp b/Source/Core/DolphinNoGUI/MainNoGUI.cpp
index 0d7a84137e..af27952ca0 100644
--- a/Source/Core/DolphinNoGUI/MainNoGUI.cpp
+++ b/Source/Core/DolphinNoGUI/MainNoGUI.cpp
@@ -80,11 +80,11 @@ void Host_RefreshDSPDebuggerWindow()
 }
 
 static Common::Event updateMainFrameEvent;
-void Host_Message(int Id)
+void Host_Message(HostMessageID id)
 {
-  if (Id == WM_USER_STOP)
+  if (id == HostMessageID::WMUserStop)
     s_running.Clear();
-  if (Id == WM_USER_JOB_DISPATCH || Id == WM_USER_STOP)
+  if (id == HostMessageID::WMUserJobDispatch || id == HostMessageID::WMUserStop)
     updateMainFrameEvent.Set();
 }
 
diff --git a/Source/Core/DolphinQt2/Host.cpp b/Source/Core/DolphinQt2/Host.cpp
index c687bb74ad..137528a791 100644
--- a/Source/Core/DolphinQt2/Host.cpp
+++ b/Source/Core/DolphinQt2/Host.cpp
@@ -75,13 +75,13 @@ void Host::ResizeSurface(int new_width, int new_height)
     g_renderer->ResizeSurface(new_width, new_height);
 }
 
-void Host_Message(int id)
+void Host_Message(HostMessageID id)
 {
-  if (id == WM_USER_STOP)
+  if (id == HostMessageID::WMUserStop)
   {
     emit Host::GetInstance()->RequestStop();
   }
-  else if (id == WM_USER_JOB_DISPATCH)
+  else if (id == HostMessageID::WMUserJobDispatch)
   {
     // Just poke the main thread to get it to wake up, job dispatch
     // will happen automatically before it goes back to sleep again.
diff --git a/Source/Core/DolphinWX/Frame.cpp b/Source/Core/DolphinWX/Frame.cpp
index 954be63fd3..8ae15c848d 100644
--- a/Source/Core/DolphinWX/Frame.cpp
+++ b/Source/Core/DolphinWX/Frame.cpp
@@ -53,6 +53,7 @@
 #include "Core/HW/GCPad.h"
 #include "Core/HW/Wiimote.h"
 #include "Core/HW/WiimoteEmu/WiimoteEmu.h"
+#include "Core/Host.h"
 #include "Core/HotkeyManager.h"
 #include "Core/IOS/IOS.h"
 #include "Core/IOS/USB/Bluetooth/BTBase.h"
@@ -186,11 +187,11 @@ WXLRESULT CRenderFrame::MSWWindowProc(WXUINT nMsg, WXWPARAM wParam, WXLPARAM lPa
   case WM_USER:
     switch (wParam)
     {
-    case WM_USER_STOP:
+    case static_cast<int>(HostMessageID::WMUserStop):
       main_frame->DoStop();
       break;
 
-    case WM_USER_SETCURSOR:
+    case static_cast<int>(HostMessageID::WMUserSetCursor):
       if (SConfig::GetInstance().bHideCursor && main_frame->RendererHasFocus() &&
           Core::GetState() == Core::State::Running)
         SetCursor(wxCURSOR_BLANK);
@@ -758,7 +759,7 @@ void CFrame::OnHostMessage(wxCommandEvent& event)
   }
   break;
 
-  case WM_USER_CREATE:
+  case static_cast<int>(HostMessageID::WMUserCreate):
     if (SConfig::GetInstance().bHideCursor)
       m_render_parent->SetCursor(wxCURSOR_BLANK);
     if (SConfig::GetInstance().bFullscreen)
@@ -776,7 +777,7 @@ void CFrame::OnHostMessage(wxCommandEvent& event)
   }
   break;
 
-  case WM_USER_STOP:
+  case static_cast<int>(HostMessageID::WMUserStop):
     DoStop();
     break;
 
diff --git a/Source/Core/DolphinWX/Main.cpp b/Source/Core/DolphinWX/Main.cpp
index ab301df0be..6e3c5938e0 100644
--- a/Source/Core/DolphinWX/Main.cpp
+++ b/Source/Core/DolphinWX/Main.cpp
@@ -415,15 +415,15 @@ CFrame* DolphinApp::GetCFrame()
   return main_frame;
 }
 
-void Host_Message(int Id)
+void Host_Message(HostMessageID id)
 {
-  if (Id == WM_USER_JOB_DISPATCH)
+  if (id == HostMessageID::WMUserJobDispatch)
   {
     // Trigger a wxEVT_IDLE
     wxWakeUpIdle();
     return;
   }
-  wxCommandEvent event(wxEVT_HOST_COMMAND, Id);
+  wxCommandEvent event(wxEVT_HOST_COMMAND, static_cast<int>(id));
   main_frame->GetEventHandler()->AddPendingEvent(event);
 }
 
diff --git a/Source/DSPTool/StubHost.cpp b/Source/DSPTool/StubHost.cpp
index f70466f882..73ef4fa19b 100644
--- a/Source/DSPTool/StubHost.cpp
+++ b/Source/DSPTool/StubHost.cpp
@@ -15,7 +15,7 @@ void Host_NotifyMapLoaded()
 void Host_RefreshDSPDebuggerWindow()
 {
 }
-void Host_Message(int)
+void Host_Message(HostMessageID)
 {
 }
 void* Host_GetRenderHandle()
diff --git a/Source/UnitTests/StubHost.cpp b/Source/UnitTests/StubHost.cpp
index b20750110a..b80f175a2f 100644
--- a/Source/UnitTests/StubHost.cpp
+++ b/Source/UnitTests/StubHost.cpp
@@ -17,7 +17,7 @@ void Host_NotifyMapLoaded()
 void Host_RefreshDSPDebuggerWindow()
 {
 }
-void Host_Message(int)
+void Host_Message(HostMessageID)
 {
 }
 void* Host_GetRenderHandle()